Techniques of liquid bleaching agents containing a boron compound and a saccharide have already been known, and Patent Publications 1 to 6 can be incorporated herein by reference. Also, these techniques also describe that the pH increases when a liquid bleaching agent is diluted.
Hydrogen peroxide is capable of exhibiting a bleaching effect in the form of a weak alkaline aqueous solution. However, since the stability of hydrogen peroxide is lowered under a weak alkaline condition, it is difficult to blend hydrogen peroxide with a neutral to weak alkaline, general liquid detergent composition, from the viewpoint of storage stability. In addition, since a commonly used bleaching activator has an active ester group, the bleaching activator quickly undergoes hydrolysis in a weak alkaline liquid detergent composition, thereby losing its activity and whereby the effect of the bleaching activator cannot be obtained at all in the actual washing situation. On the other hand, because stains due to spilled foods and the like can be effectively removed by bleaching, it is earnestly desired that hydrogen peroxide and a bleaching activator give a bleaching effect to a liquid detergent.
For the purpose of satisfying both the stability and the bleaching effect of hydrogen peroxide, techniques of making the pH of a manufactured article of a liquid detergent composition weakly acidic and raising the pH by diluting the liquid detergent composition with water have been known, and described in Publications 1 to 6 (hereinafter referred to as (pH jump system, or pH jump effect)). These techniques are accomplished by using together a boron compound and a polyhydric alcohol such as a saccharide. However, in many of these techniques, while the pH of a composition is adjusted to 4.5 or less and the pH jump effect is exhibited, the pH reached is less than 8. With such a dilute pH, the expected bleaching effect is insufficient. Even in the case where a bleaching activator is further used, the formation rate of an organic peracid from the bleaching activator is markedly delayed. Therefore, not only is the bleaching effect to be expected insufficient, but also the washing effect is also not satisfactory.
Patent Publication 7 discloses a branched bleaching activator, describing that the bleaching activator has excellent stability in a liquid bleach composition. However, this publication does not suggest at all that a liquid bleach composition is free from the disadvantage in the stabilities of both hydrogen peroxide and a bleaching activator at a pH of 4.6 or more in the pH jump system, or moreover that an organic peracid in a satisfactory amount is formed from a bleaching activator when diluted with water.    Patent Publication 1: JP-A-Hei-6-100888    Patent Publication 2: JP-A-Hei-7-53994    Patent Publication 3: JP-A-Hei-7-70593    Patent Publication 4: JP-A-Hei-10-72595    Patent Publication 5: JP 2000-144187 A    Patent Publication 6: JP-A-Hei-10-72596    Patent Publication 7: JP-A-Hei-10-251689